1. Field of the Invention
The present invention relates to a projection system which projects a color image on a screen utilizing projector devices.
2. Description of the Related Art
Conventionally, in order to display a highly precise image on a large screen, a projection system has been proposed, in which a plurality of projector devices are used to project a color image on a screen.
FIG. 8 shows a conventional projection system in which the same projector devices are arranged.
As shown in FIG. 8A, this projection system is configured so that four (2×2: first to fourth) projector devices including a first projector device 101 and a second projector device 102 are arranged. In a screen 103, images projected from the first and second projector devices 101 and 102 are displayed on neighboring first and second areas 1031 and 1032.
In the screen 103 shown in FIG. 8B, first to fourth areas 1031 and 1034 are shown, on which images are displayed through the first to fourth projector devices. The first to fourth projector devices is assigned to display the areas 1031 and 1034, each of areas 1031 and 1034 being a quarter of the screen 103.
FIG. 9 shows a projection system, which projects images from the same projector devices on the same area.
As shown in FIG. 9A, four (2×2: first to fourth) projector devices including a first projector device 111 and a second projector device 112 display images on the same area of a screen 113. On the screen 113, pixels projected from respective projector devices are arranged so that these pixels are shifted 0.5 pixels as for the minimum pixel unit with each other. Consequently, as a result, the image displayed on the screen is assumed to be equal in the case where the pixel size becomes half, which leads to a highly precise image.
When a part of an area 113a on the screen 113 shown in FIG. 9B is enlarged, as shown in FIG. 9C, the pixels from the first to fourth projector devices are shifted 0.5 pixels with each other. Specifically, the first pixel from the first projector device 111 depicted as the symbol “circle”, the second pixel from the second projector device 112 depicted as the symbol “star”, the third pixel from the third projector device (not shown) depicted as the symbol “triangle”, and the fourth pixel from the fourth projector device (not shown) depicted as the symbol “asterisk” are arranged so that the positions are shifted 0.5 pixels with each other in the horizontal direction and/or the vertical direction.
In the projection system where the projector devices are arranged as shown in FIG. 8A, precise matching is required at the joint (depicted as broken line a in FIG. 8B) between the images assigned to the respective projector devices. Also, when the number of the pixels is doubled, the number of the projector devices should be increased by a factor of four, leading to a large-scale system.
In the projection system shown in FIG. 9A where images are projected from a plurality of the projector devices on the same area, it is difficult to perfectly shift the images 0.5 pixel over the entire area of the display because of the influence of the deformation of the lens between the projector devices.
An object of the present invention is to provide a projection system, which is composed of a small number of constituents and which can display a highly precise image.